In recent years, research into display devices has been actively conducted to achieve higher fineness by making pixels denser. One particular pixel structural arrangement for achieving higher fineness is based on the visual characteristics of the human eye, wherein the visual resolution for the range of blue wavelengths is lower than that for the range of red or green wavelengths. As an example of such a pixel arrangement, a hexagonal pixel structural arrangement forming a honeycomb structure is disclosed. The pixel structural arrangement is composed of hexagonal blue pixels arranged in the center and red and green pixels alternately arranged to face respective sides of the blue pixels.
In a display device having the above pixel structural arrangement, the constituent ratio between red, green, and blue is 3:3:1, and the number of blue pixels, for which the visual resolution is low, is small. Thus, the display device can display images with high quality and a small number of pixels.
Even in the display device having the above pixel structural arrangement, at least three pixels of red, green, and blue are necessary as the minimum units for displaying color images. Each pixel comprises a region which does not contribute to display, such as switching elements and various lines. Thus, if each pixel is miniaturized to produce higher fineness, the area of an opening contributing to display in each pixel cannot be sufficiently secured, and the transmittance of a display panel may decline. In addition, to obtain sufficient transmittance with an opening small in area, the brightness of a light source which irradiates the display panel needs to be increased. Thus, power consumption may be increased.